Switched reluctance motors have simple and robust structure, and are suitable for use in harsh industrial environments; however, the existence of position sensors results in severely reduced motor reliability, increased motor cost and system complexity. Moreover, since position sensors can not be mounted in some domains (e.g., compressor applications), the applicability of switched reluctance motors is severely limited. Therefore, it is an inexorable trend to implement control without position sensor in the development of switched reluctance motors. A variety of controlling methods without position sensor have been put forward at home and abroad. For example, measure the flux linkage characteristic or inductance characteristic of a given motor in online or offline mode, establish a motor model in the form of a table, fitting function, or neural network and store the motor model in a controller, measure the flux linkage or inductance of the motor in real time during the motor operates, and deduce the rotor position through the model in conjunction with the present phase current. Since the given motor is required to be modeled in advance in this method, the universality of the method is limited; in addition, to measure the flux linkage (or inductance) in the modeling process or operation process, data acquisition and computation has to be carried out for a number of variables, resulting in error accumulation and degraded position detection accuracy; moreover, the detection error will be increased since the model is susceptible to the impact of motor aging. The rotor position at the end position of minimum phase inductance can be obtained through phase current gradient method by detecting the peak phase current in the inductance rising zone; that method is not suitable for phase current chopping control; the ON-OFF angle adjustment range is limited, and the speed adjustment range is reduced during angular position control.